The 28-year-old Bolton native has boxed just once this year while waiting for a marquee fight to be arranged and, while no paperwork has yet been exchanged, his patience looks increasingly likely to be rewarded.

A source close to Khan confirmed the fight has been agreed in principle between the two camps for a contest, likely to be next April in the United States, although there is still some way to go before it becomes official.

Quotes from both Khan's father, Shah, and Pacquiao's promoter, Bob Arum, have been flying around in recent days with the camps contradicting each other.

"Our paperwork went off to Arum on Friday and every point is covered," Khan Senior reportedly said. Arum denied this, but it is understood that both sides have agreed to the contest in principle.

A fight between Khan and former pound-for-pound king Pacquiao would be a huge event, given Pacquiao's profile and Khan's marketability on American television.

Added spice would be provided by the history between the two men, who trained together and sparred regularly when Khan was trained by Pacquiao's mentor Freddie Roach.

Khan once vowed never to fight his "friend" but their relationship has cooled markedly since the Englishman split from Roach to join forces with current trainer Virgil Hunter.

Pacquiao, meanwhile, has been considering his options while recovering from a shoulder injury which he blames for his lacklustre defeat by rival Floyd Mayweather in May.

While Khan would be a logical next move for the 36-year-old Filipino, he is also considering a clash with Terence Crawford or even former foe Timothy Bradley.